Signal transmitter



April 14, 1925. 1,533,542

J. H. DERBY SIGNAL TRANSMITTER Filed June 17, 1922 5 Sheets-Sheet 1 April 14, 1925.

J. H. DERBY SIGNAL TRANSMITTER Filed June 1' 1922.

5' sheets-sheet z April 14, 1925- I 1,533,542

- J. H. DERBY SIGNAL TRANSMITTER Filed-June 17, 1922. 5 sheets-sum a Vi aavwemtcz J. H. DERBY SIGNAL TRANSMiTTER Filed June 1'7, 1922 5 Sheets-Sheet 5 E 2 W. L oww AN N g m NE mom m xukm wum 3w %w\ OWN wvw @T A M FL mww Q m (I! V 1 v nmwt o m wagon 8n VMN BY M IIHU i etented Apr. 14, 1925.

UNITED STATES PATENT OFFIQE.

JOHN DERBY, on NEW YGRK, N. Y.

SIGNAL TRANSMITTER.

Application filed June 17, 1922. Serial No. 569,089.

To aZZ whom it may concern: and ratchet for retaining the driving spring Be it known that 1, JOHN HfDnnnY, a in wound condition; citizen of the United States, residing at New Fig. 5 is a perspective detail of the con- York city, N. Y., have invented certain new tacts or switch members associated with the 5 and useful improvements in Signal Transmeans for Operating the box by hand and mitters, of which the following is a clear, for testing the operation of the box without full, and exactdescription. transmitting a signal;

This invention relates to transmitter boxes Fig. 6 is a detail view showing the escapesuch as are used in connection withv fire ment associated with the makeand-break 10 alarm and other signal transmitting systrain of mechanism;

tems, and has for its general object to im- Fig. 7 is a sectional view showing the reprove the construction of such boxes with sistance contained in the box and the means respect to the simplicity and the durability for shortcircuiting this resistance; oi the mechanism, and also with respect to Fig. 8 shows the box tripping mechanism certainty of operation and automatic super in its normal retaining position; vision. The invention aims particularly to Fig. 9 shows the tripping mechanism in devise a transmitter box and an associated its tripping position; signal system which has especial utility in t Fig. 10 is a perspective detail of the armahotels, hospitals and other places where it ture and its associated releasing spring; 20 is desirable to have means for transmitting Fig. 11 is a view, onehalt scale, of the either a. silent alarm or a general alarm ininner face of the box cover; eluding a warning signal to the people in Fig. 12 is a wiring diagram of the box 7 the building. and the associated control board, and

Important features of the invention are Fig. 13 is a wiring diagram of the trouble the provision in a transmitter box supercircuits constituting a part of the automatic vised by a normally closed circuit including means for supervising the box and its cona trip magnet in said box of means associnected signal system. S0 ated with the armature of said magnet for The illustrated transmitter box comprises insuring the separation of the armature an enclosing casing, which is shown as a 30 "from the magnet when the operating current cylindrical box 2, of bronze, iron or other is cut down so that only the supervising cursuitable material, having a cover plate 4 rent is left in the circuit; the provision of which is removable to permit inspection of means for automatically supervising a northe mechanism of the box, only a small part. mally open code signal circuit; the provision of the mechanism of the box being carried of means for automatically indicating when by the cover plate. the box is run down, and the provision in The train of mechanism through which the box of resistance which may be short the make-and-break signal transmitting 9o circuited to cause the operation by the break means of the box is operated is carried by a wheel of a normally open but automatically frame comprising front and rear plates 6 40 supervised floor circuit. and 8 suitably spaced by posts 10, the plate Other objects and important features of 8 being attached to the rear wall of the the invent-ion will appear from the followcasing or box 2. .The train of mechanism iug description and claims when considered comprises a segment gear 12 rigidly attached in connection with the accompanying drawto the drum portion l i (see Fig. of the 45 ings, in whichspring shaft 16, the drum portion 1% of this Figure 1 is a front elevation of transshat't having attached thereto a driving initter box en'ibodying the invention, with spring 18, the outer end ojt'which is conthe cover removed; nected to one of the posts 10. It will be Fig. is a plan view of the transmitter noted that the drum portion 14: on: the shalt 50 mechanism, the box being shown in section; 16 has shoulders abutting the plates ('3 and 8 Fig. 8 is a section on the line 33 of whereby it also helps to maintain these Fig. 1; plates properly spaced.

Fig. i is a detail view showing the pawl The segment gear 12 meshes with a pinion 20 upon a shaft 22 having its hearings in the plates 6 and 8, the shaft 22 also having rigidly attached thereto a gear 24: meshing with a pinion 26 upon another shaft 28 having its bearings in the plates 6 and 8, the last mentioned shaft having rigidly attached thereto a ratchet wheel 30 adapted to be engaged by a spring-pressed pawl 32attached to a gear wheel 34E free to turn on the shaft 28. The gear wheel 3% meshes with a pinion 36 upon a shaft 38 having its hearings in the plates 6 and 8. The shaft 38 also has rigidly attached thereto an escapement wheel 4-0 with which cooperate escapement pallets a2 and is: connected together in the usual-manner and oscillating upon a short shaft 46 having one of its bearings in the plate 6 and its other bearing in a bracket 48 attached to the inner face of the plate 6. A suitable fan plate 50 (see Fig. 6) attached to the escapement pallets controls the rate of oscillation of the escapement pallets and thus the speed of the make-and-break train.

The make-and-break or code wheel 52 is shown in Fig. 1 attached to the front end of the shaft 28 which extends through the bearing plate 6, the 111ake-and-break wheel being rigidly attached to the shaft 28 in any suitable manner, as by the set screw 5st, which permits the removal of the wheel and the substitution of another wheel having thereon a differentcode.

The shaft 16 associated with the spring 18 is sufliciently long so that its end 56, which is squared to receive a winding key, extends to the outside of the cover 4; of the box.

The train of mechanism whiclroperates the make-and-break or code wheel 52 is normally held against operation by tripping mechanism now to be described. This tripping mechanism comprises a detent or dog 58 pivoted upon the shaft 22 and having one end shaped to engage a pin 60 011 the gear wheel 3% to hold this wheel against its tendency to turn in the direction of the arrow in Figs. 8 and 9 under the action of the drivspring 18, the segment gear 12, pinion 20, gear 2st, (see Fig. 3) and the pinion 26 on the shaft 28, to which the ratchet wheel 30 engaged by the pawl 32 on said gear 3% is rigidly attached. At its other end the detent or dog 58 carries a pin 62 which engages the shoulder 6 f of an opening in a lever 66 fulcrumed at 68; on the front face of the plate 6. The opening in the lever 66 has an enlargement 70 below the shoulder Get into which the pin 62 on the detent 58 may drop to cause the lower end of the detent 58 to move up out of engagement with the pin 60 on the gear 3 1-. A spring '72 connected at one end to a pin Tet on the detent 58, and at its other end to a pin 76 on the lever 66, tends normally to hold the pin 62 on the detent against the shoulder 6% on the lever, and to cause said detent to swing as far aspermitted by the enlargement 70 when the lever 66 is rocked about its hearing 68 sufficiently to move the shoulder 64 out of engagement with the pin 62.

The last mentioned movement of the lever 66 is preferably effected automatically through the trip magnet and its associated armature now to be described. The trip magnet 7 8 is supported by a bracket 80 attached to the rear wall of the box, and the armature 82 of this magnet, as shown in Figs. 2 and 10, is preferably carried upon a lever or bar 8a having an anti-friction hearing comprising a shaft 86 rigidly connected to said bar or lever 84:, the shaft 86 having hardened cones 88 at its end to enter correspondingly hardened bearings, one of which, shown at 90, (see Fig. 2) is preferably adjustable.

The lever or bar 84: at its end remote from the bearing carries a pin 92 which is received in a slot 9% in the lever 66. this slot being so located that the movement of the bar or lever Set with the armature 82 toward and away from the magnet 7 8 effects the rocking of the lever 66 about its fulcrum 68, thus effecting the tripping and permitting the resetting of the box.

An important feature of the invention is the provision of' means for insuring the movement of the armature 82 away from'the magnet 7 8 when the current in the circuit is reduced below operating level so that the box may be reset. As hereinabove suggested, the box is preferably supervised by a closed circuit maintained below operating level,

and to overcome the residual magnetism in the magnet and any tendency of the armature to stick due to corrosion, adhesion, atmospheric pressure or other causes, the armature is preferably provided with a spring 96 operating between the armature and the magnet. *As shown in Figs. 1 and 10, this spring 96 is preferably located in a recess 98 in the contact face of the armature in such manner that when the armature is attracted to the magnet by a. proper operating current, the spring 96 will be bent down until it is received in the recess 98, thus permitting the contact face of the armature 82- to be brought into actual contact with the cooperating face of the magnet 78. lVhen, however, the current through the magnet 78 is reduced to below its operating level to its supervising level, the spring 96 will act to break the contact between the face of the armature 82 and the cooperating face of the magnet 78, thus permitting the armature with its associated lever 84 to move away from the magnet '78 and permit the re-setting of the box.

The resetting of the box is preferably effected automatically near the end of the movement of the segment gear 12 toward the run-down position of the box. The segment gear 12 carries a pin 100 projecting from its front side, as shown in Fig. 2 of the drawings this pin projecting forwardly sufliciently so that it will engage the curved under face of the detent 58 as the segment gear 12 moves toward its run-down position, and swing the detent suiiiciently so that its pin 62 will be in position to be engaged by the shoulder 64, and its lower end will be in position to be engaged by the pin on the gear wheel As above stated, this engagement by the pin 100 takes place toward the end of the movement of the segment gear 12 toward its run-down position.

To insure the dropping of the lever 84 by the reduction of the current through the .n'iagnet 7 8 below its operating level so that the box will be automatically reset at the end of the ope 'ation thereof, provision is made for the breaking of the circuit through the magnet 7 8 as the segment gear 1.2 approaches its run-down posit-ion, provision being also made for giving a run-down signal at this time. The illustrated means for effecting the breaking of the circuit through the magnet 7 8 comprises a roll or stud 102 (see Fig. 1) carried upon thev front face of the segment gear 12 in such position that as the gear 12 approaches its run-down posi-u tion this roll or stud 102 will engage the spring member 104 of a circuit-breaking switch and separate the contact members 106 and 108, this switch being in the circuit through the magnet 78. Separation of these members not only permits the dropping of the armature 82 and with it the lever 84, thus restoring the lever 66 to its retaining position with respect to the detent 58, but the breaking of the circuit also gives a trouble alarm by closing a trouble circuit hereinafter to be described.

The make-and-break or code wheel 52 is shown in Fig. 1 in its normal position of rest' in which the switch arm 110 of the make-and-break mechanism rests upon a part of the code wheel sufliciently high to maintain the contacts 112 and 114 in engagement, the contact 114 being carried by a second spring arm 116 which on its upper face carries another contact 118 in engagement with the contact 120 on the arm 122 when the spring arm 110 is resting on the part 124 of the code wheel The depressions between the teeth 126 of the code wheel are sufficiently low so that when the spring switch arm 110 'drops into one of these depressions not only is the circuit broken by the separation of the contact members 112, 114, but a. second circuit is also broken by the separation of the contact members 118, 120.

in addition to the automatic make-and break mechanism just described, the box is also preferably provided with hand operated switches by which the operation of the box may be tested and by which other signals than the code signals may be sent. In the illustrated construction, a spring switch arm 128 is shown as provided with two contacts 130 and 132, the contact 130 being normally in engagement with a contact 134 on a spring arm or conductor 136, and the contact 132 being adapted to be moved into engagement with the contact 138 on an arm 140. c

The means for moving the switch arm 128 to effect either the separation of the contacts 130 and 134 to break the circuit in which they are included, or the engagement of the contact members 132 and 138 to complete av circuit of which they form apart, comprises a lever 142 having a rectangular slot 144 into which the free end of the switch arm 1.28 extends, this lever 142, as shown in Figs. 2 and 3 of the drawings, being attached to a short shaft 146 having its bearings in a plate 148 upon thefront face of the plate 6, and in a bracket 150 attached to the plate 148, the shaft 146 extending through the cover plate 4 of the casing and being provided with a squared outer end 152 to receive a key by which the swinging of the lever 142 against the tendency of the spring 154 to hold it in the position shown in Fig. 1 may be effected. It will be seen that the lever 142 may be swung in either direction about its axis, and that when swung in a. clockwise direction it brings the contact 132 into engagement with the contact 138 and closes the circuit of which these form a part, and when swung in a counterclockwise direction, Fig. 1, it effects the sep aration of the contacts 130 and 134 and breaks the normally closed circuit in which thev are included. i

The box is also preferably provided with a resistance element which may be in the form of a coil 156, the illustrated coil being shown in detail in the sectional View in Fig. 7 of the drawings. It will be noted that two leads 158 and 160 come into the same end of the coil, these leads being connected respectively to conductors 162 and 164 shown in plan view in 1, and one of the leads 160 being also connected to one end of the resistance winding of the coil, the other end of this winding being connected to a lead 161 at the other end of the coil. The conductors 162 and 164 are separated but have opposed recesses so arranged that a short-cirouiting spring key 166 may be inserted into the hollow center 168 of the coil in such manner that it engages the two con ductors and short-circuits the coil, thus cutting the resistance out of the circuit in which it would normally be included when the key is not in the position shown'in Fig.

Having reference now to F 12 of the drawings, it will be netted that the trip magnet 78 is in a circuit coi'nprising a wire 170 coming in upon the control board 1'72 at 1T4, and that the other wire 17 6 from the magnet 7 8 comes in from an outside circuit which may include a release box 178, one side 180 of a two-wire circuit coming in upon the control board at 182, a trouble relay magnet 18 1- upon the control. board, and the other side 186 of the two-wire circuit leaving the control board at 188 and returning to the heard through the switch 108 and 106 of the transmitter b0 and coming back upon the board at 190.

Current for su 'iervising and operating the mechanism upon the control board and the mechanism in the transmitter box may be supplied "from the city mains, or a battery, or other suitable local source, and in the illustrated control board is shown as lnought upon the board at the positive terminal 192 and as leaving the board atthe negative terminal 194, the two-wire circuitjust described being connected to the positive terminal 192 through the wire 196 and the use 198 and being connected to the negative terminal through the wire 200, the switch 202 non mally short-circuiting the ammeter 20 1, and through the balancing resistance 206 and the fuse 208.

The trouble relay magnet 18 1 at the end of the two-wire circuit just described constitutes resistance sutticient to cut down the current brought in upon the control board 172 below the level at which it will operate the release box 178 and the trip magnet 7 8. This resistance may be short-circuited out of the circuit in any suitable manner as, for example, by means of fusible thermostats 210 oi the type shown and described in the Letters Patent of John H. Derby and Ernest Seymour Clayton, #1274218, dated July 80, 1918, or by means of a hand-operated short-circuiting switch in the transmitter box, this switch comprising an upper spring switch arm 212 carrying a contact 21 1, and a lower switch arm 216 carrying a. contact 218.

As shown in Figs. 1, 2 and 11, the switch arm 21 has upon its upper side a small cam 220 adapted to be engaged by a stud or roll carried upon an upwardly extending arm 22% of a. lever tulcrumed at 226 on the inner face of the cover 41 of the box. (see Fig. 11). A pin 228 on the lever 22a projects through a slot 280 in the cover plate l. and carries upon the outside of said box a knob or handle 232 by which the pin 22 may be moved up and down in the slot 230, thus rocking the lever 224s and causing the stud or roll 222 to press down upon the cam 220 and force the contact 21% into engagement with the contact 218, thus short-circuiting the trouble relay 18 1 and causing an increased flow of current through the circuit, including the release box 178 and the mag- .cated, wire 2-18. wire net 78, this increase ct current being su'l'licient to operate the release box and trip the automatic transmitter mechanism.

Any break in the circuit just described would cause the trouble relay 181- to drop its armature 23st and close the circuit through a trouble gong hereinafter to be described. As hereinabove described, the circuitis broken by the separation of the contacts 106,

108 when the transmitter box runs down, as

shown in Fi g. 1 of the drawings, thus giving a trouble alarm.

The circuit for the make-and-brcak signal transmitting mechanism shown in Fig. 12 comprises a wire 236 leading from the spring switch member 112 thromgh the switch arm 128, through the contacts 130 and 134, switch member 136, wire 2238, trouble relay magnet 2&0. wire. 2,42, gong 2&4, which may be located in the ollice or engine room, register 216, also similarly lo- 250, balancing resistance 206, fuse 208 to the negative terminal 19% on the board, the other side of the circuit comprising the switch member 116, wire 252 and wire balancing resistance 256, fuse 198 to-the positive tern'iinal 192.

The second make-and-break circuit is a normally open circuit adapted to be closed by the short-circuiting key 166 associated with the resistance coil 156, this circuit comprising the switch member 122, wire 158 leading to one of the contact members 162, 16% of the resistance element, and the wire 160 leading trom the other contact member of said resistance element to a double-ended relay magnet 260 from which a wire 26l leads to a trip magnet 266 of an outside transmitter box of the city alarm system, the negative side of the circuit being completed by wire 268 to wire 250, back to the negative terminal 19%, the positive. side of this circuit including the switch member 116, and the wires 252 and 25 1 to the positive terminal.

The resistance. 156 is connected between the. wires 160 and 252 so that a supervising current flows through this resistance 156 which supervises the circuit including the relays 260 and 266., one end of the relay 260 being associated with a trouble circuit. hen the key 166 is inserted between the contact members 162 and 16%, the resistance 156 is short-circuited and sufficient current is permitted to flow through the relay 260 to draw down the armature 270 and close the circuit which includes the wire from the positive terminal 192, the wire 272, ha]- ancing resistance 27 i, tloor gong 276, 278, 280 and wire 282, back to wire 250 and the negative terminal 194-. Thus when the resistance 156 is cut out of the transmitter box, a coded signal will be sent to each floor upon the manual tripping of the transmitter, giving a local alarm for arousing the occupants of the building. The increased flow of current will also energize the magnet 266 sufliciently to trip the code transmitting wheel 284 for sending an alarm to the fire station.

The normally open code signal circuit which includes the floor alarms is supervised by a. current passing through the trouble relay magnet 286, the positive side of this circuit coming to the relay magnet 286 through the wires 254, 252, the resistance 156, and the wires 160 and 288, and the negative side of this circuit coming to the relay 286 through the wires 290, 272, resistance 274, single stroke goings 276, 27 8, 280 and wires 282 and 250.

In order to operate the transmitter box, that is, particularly the train of mecha nism including the code wheel, without transmitting a code signal, as for example when it is desired to test the mechanism, means are preferably provided for short circuiting the code signal transmitting circuit, the illustrated means comprising the switch arm 128, the contacts 132 and 138 and the switch member 140, the contact 132 be ing adapted to be moved into circuit-closin-g relation to the contact 138 through the turning of the lever 142 in a clockwise direction. As shown in Fig. 12 ot the drawings, this short-circuits the code transn'iitting switch members 116 and 1.10 through the switch. member 140 and the wire 292 leading back to the wire 161. Turning oi? the code wheel 52 will, therefore, have no ciiect upon the circuit which is now com pleted through the switch members 140, 128 and 136.

The troublerelays and trouble signal circuits are shown diagrammatically in Fig; 13 of the drawings, there being four of these trouble relays, 184, 240, 260 and 286, each normally in a closed circuit, the re spective circuits supervised by these four relrys having been hcreinabove described. Each of the relays has associated therewith an arn'iature normally held by the current passing through the closed circuit in which the relay is included out of circuit-closing relation to a cooperating contact member in a circuit which includes the trouble alarm 294. In the case of the relays 184, 240 and 286, the: respective armatures 234, 296 and 298 are arranged to gravitate into circuitclosing relation to the respective cooperating contacts 300, 302, 304, while in the case of the armature 306 of the horizontal relay. magnet 260 a spring 308 is provided which tends to move this armature into engagement with the co-operating contact member 310. From an inspection of the wiring diagram in Fig. 13, it will be apparent that whenever a circuit including any of the. relays is broken, the movement of the associated armature thus released will. complete a circuit through the trouble alarm 294 and the local trouble circuit battery 312.. i

In order that the train of mechanism operating the code wheel may be released when there is no current passing through the transmitter box or through the circuit which includes the magnet 78, the lever 224 (see Figs. 2 and 11) is preferably provided with an arm 314 which extends beneath the lever 84 so that when the knob or handle 232 is pushed downward the upward movement of the arm 314 of the lever 224 will effect the movement of the lever 84 and the associated armature 82 toward the magnet '7 8, thus tripping the train of operating mechanism for the code wheel in the same manner that it is tripped automatically by the energizetion of the magnet 7 8.

From the foregoing description, the operation ofthe transmitter box will readily be understood. If one of the thermostatic circuit controllers 210 becaused to short circuit the trouble relay magnet 184, which is of suiiicient resistance to maintain the current in the circuit including these thermostatic elements ata supervising level and below 0 aeratin level, the increased current flow caused by the short-circuiting ot the relay magnet 184 will operate the release box or boxes 178. Such release boxes are usually employed to effect the .closingo'l fire doors,-dip tank covers and the stoppingot blowers and other machinery that might increase the fire hazard. The increased current flow will also energize the magnet 7 8 sufficiently to cause it to draw the armature 82 and with it the connected lever 84, thus moving the shoulder 64 on the lever 66 out of engagement with the pin 62 on the detent 58, whereupon the spring 72 causes the detent 58 to rock until its end is out of engagement with the pin on the gear wheel 34, thereby releasing the train of operating mechanisms for the code'wheel 52.

The spring 18 being wound up and the segment gear 1.2 being in the position shown in F 8 of" the drawings, the release of the operating mechanism by the movement of the detent 58 out of engagement with the 1 pin 60 permits the segment gear 12 to be .moved upward in the direction of the arrow, Figs. 8 and 9, thereby, through the train of pinions and gears, driving the code wheel 52 and causing it to transmit a coded signal to the local gong 244 and to the register 246, which may be in the engine room or in the office of the building, it being 0bvious, of course, that signals may be provided in both places if desired. This coded signal is sent through the circuit, including the switch member 110, wire 236, switch member 128, switch member 136, wire 238,'

ters or to the floors of the building.

If now it is desired to make the alarm general and give warning to the occupants of the building and at the same time send an alarm to fire headquarters, the plug or key 166 is inserted between the contact members 162 and 164 to short circuit the resistance 156, whereupon the increased flow of current through the circuit, including the switch members 116, 122, the wires 158, 160, the relay magnet 260, wire 264, the trip magnet 266, wire 268, wire 250, negative terminal 194:, positive terminal 192, wires 254i, 252 and 161, will cause a coded signal to be sent to the building floors by the drawing down of the armature 270, closing the circuit through the single stroke gongs 276, 278, 280, and will cause the tripping of the outside signal box containing the code wheel 28 1 for transmitting an alarm to fire headquarters, said box being reset either before or after the key 166 is inserted and again tripped, this tripping being effected by hand. The resetting of the box is effected by winding the spring 18 through a key upon the shaft 16 as hereinabove described.

As the transmitter box runs down and the segment gear 12 approaches the upper limit of its movement, the stud or roll 102 on this segment gear engages the switch member 104: and separates the contacts 106, 108, thus breaking the circuit including the trouble relay magnet 184, thereby permitting its armature 234 to drop into engagement with the cooperating contact member 300 whereupon a trouble signal is given by the trouble alarm bell 294 Should the watchman or other person iiitending to operate the box desire to send an alarm to fire headquarters without operating the lotal alarm, this can be done by simply plugging in the key 166 to short circuit the resistance 156 when the box is at rest. This will result in the bells 276, 278, 280 being given a single stroke but not a coded alarm and in the energization of the tripping magnet 266. If, after doing this, he still desires to send a coded alarm throughout the building, he can then pull down on the knob 232, thus both short-circuiting the resistance 18% in the circuit which includes the trip magnet 78 and also positively lifting the lever 8% to effect the positive tripping of the train of mechanism which drives the code wheel The circuit making-alid-breaking action of the code wheel o2 will then cause a coded signal to be sent throughout the building, This short-circuiting action will also effect the operation of the release box 1.78.

From the foregoing description it will be seen that the box is arranged to be operated both automatically and manually, and that it is also arranged either automatically or manually to give a local alarm only, an alarm to fire headquarters only, or both a local alarm and an alarm to fire headquarters. It will also be seen that all of the circuits, including the normally open circuit to the floor alarms, is under supervision and that whenever a break occurs in any of these circuits a trouble alarm isgiven.

From an inspection of Fig. 1 of the draw ings, it will be noted that when the armature 82 and its attached lever S lis in retaining position, the spring 96 carried by the armature is not under tension and that it is notbrought under tension until the armature has moved sufliciently toward the magnet, when the magnet has been energized, to bring it into the field of strong magnetic action. At the same time, the interposition of the spring 96 between the armature and the magnet serves a further purpose in that it makes the transmitter mechanism substantially jar-proof. In other words, the spring prevents a suflicient upward movement of the armature 82 and lever 81 when the box is jarred to permit the tripping of the mechanism.

This is a particularly important feature of the present invention as it prevents the tripping of the transmitter and the sending of a false alarm due to vibration or arring of the transmitter. The accidental tripping of the transmitter in this manner has been a common occurrence in transmitters hereto fore produced.

lVh-at I claim as new is:

1. In an electric signal transmitting sys tem,,a transmitter box and a local signal circuitthrough which said box is ar'anged to transmit local signals, a second transmitter box and a circuitthrough which it transmits signals to headquarters, connections between the first box and the second transmitter box resistance in the connections to said second transmitter, and means at said first transn'iitter for cutting out said resistance when it is desired to automatically transmit a signal to headquarters.

2. In an electric signal transmitting system, a transmitter box having therein make-andbreak signal transmitting means normally in closed circuit condition, a trouble relay in said circuit for indicating a break in said circuit when said transmitting means is not operating, through said transmitter box controlled from said transmitter mechanism for governing the sending of signals to headquarters, said second circuit being also normally closed except through said shunt, re-

a second circuit including a shunt sistance in said second circuit arranged to he sliort-circuited by closing said shunt and a trouble relay in said second circuit for indicating a break in said circuit.

In an electric signaling system, the combination with a transmitting device comprising a make-and-break code signal transmitting wheel, a normally open relaycontrolled signal circuit associated with said code wheel, a relay circuit also associated with said code wheel and having resistance therein normally maintaining the current in said circuit below relay operating level, means at said transmitting device for shortcircuiting said resistance, and means for bridging the normally open signal circuit at said relay, said means including a trouble relay wound to provide a supervising current for said signal circuit below the signal operating level.

*l. In an electric signal t ansmitting system, the combination with a code signal transmitting device, includin a code wheel and makc-and-break switch mechanism, oat separate normally closed circuits controlled by said malre-and-breal; switch mechanism, one of said circuits including signaling means directly in circuit with said switch mechanism, and another circuit including a relay, resistance in said relay circuit maintaining the current in said circuit below relay operating level, and means a said transmitting device for short-circuiting said resistance to operate said relay.

In an electric signaling system, a transmitter box adapted to control the transmission both of local signals and of signals to fire headquarters, said box having the-rein. signal transmitting means includ ing a code wheel and malte-and-break switch mechanism operated by said code wheel, separate normally closed circuits controlled by said make-and-break switch mechanism, one off said circuits including signaling means directly in circuit with said switch mechanism, another circuit including means "for actuating a fire headquarters transmit te r, resistance in said lastmentioned circuit maintaining the current therein below the operating level of said actuating means, and means in said transmitter box for short-circuiting said resistance to raise the current in said last-mentioned circuit to operating level.

6. In an electric signal transmitting system, the combination with a code signal transmitting device including a code wheel and make-and-break switch mechanism, of a plurality of normally closed circuits controlled by said make-and-break switch mechanism, one of said circuits including sign a ling means directly in circuit with said switch mechanism and operable by the nor-- mal current flowing thri'iugh said circuit, an other circuit including a relay and also means for actuating a fire department tran smitter, resistance in said. last-mentioned circuit normally maintaining the current flow therein below operating level for said relay and for said actuating means, a local floor gong circuit controlled from said relay, and means at said transmitting device for short-circuiting said resistance to cause the operation of said local gongs through said code wheel and the transmission of a signal to fire headquarters.

Signed at New York city, N. Y., this 15th day of June 1922.

JOHN H. DERBY. 

